Tomb of the
Ancients Secret Place
In the last location in Tomb of the Ancients, on the dark area n the 3rd panel behind the "Technical Check-Up" door, press the buttons "B, Y, D-Pad Right, D-Pad Left, D-Pad Right, D-Pad Left". A crate will appear that permits you access to a hole in the wall if you were in the right location when you got in the code. In this hole, you can see numerous tricks about the game.
On your controller Press B, Y, Right, Left, Right, Left at the "Access Denied" display that appears after you finish a level without gathering all lums and cages. The word "Cheat" will appear under the "Access Denied" message to verify proper code entry.
Easy Ammo at The Crow's Nest
Fly to the highest point of the roofing in the level and keep attempting to strike the. Hold B + Y till you strike it. You will teleport into a metal pipeline structure if done properly. Reach completion of this structure and you will teleport back to the main location. The orange balls of ammo that typically appear will now be blue, and will never ever run out unless you get struck.